Swivel-up dispensing packages have been used to dispense cosmetic cream products to the axillae of the user. Typically, the product is moved to the outer end of the dispensing package by manually turning a hand wheel, which drives a feed screw and, in turn, an elevator. Moving the elevator into the product pressurizes the product causing the product to be extruded through the orifices of a perforated dome onto the applicating surface of the perforated dome.
An undesirable side effect of this type of dispensing package which occurs when cream products are used is that after the product has been dispensed there exists residual pressure within the product in the dispensing package against the perforated dome causing the product to weep onto the applicating surface of the perforated dome for a period of time after the user has ceased dispensing. Depending upon the material properties of the cream product contained in the dispensing package, product separation may occur and individual components of the cream product could spread onto the applicating surface. Either occurrence results in a soiled, undesirable appearance of the applicating surface and may also negatively affect application aesthetics. Furthermore, after the product and/or its components, have weeped (defined as a liquid component separating from a product's chemical or physical matrix) onto the applicating surface, the product, or its components, may spread to the outer wall of the container body and soil the hands of the user.
One approach to relieving the residual pressure on the product is to utilize a dispensing package having a feed screw to drive an elevator which impels the cream product in a unidirectional manner. The drive of the feed screw is superimposed with reciprocatory motion caused by an internal cam. When the feed screw moves up the internal cam the pressure on the product increases and product extrusion through the perforated dome occurs. An integral spring or a separate spring can be used on the feed screw to retract the feed screw and elevator once the internal cam has reached its apex position. It is important to have the elevator surface match the internal topography of the perforated dome and to have the elevator move perpendicular to the feed screw without wobbling (defined as teetering or moving unsteadily in an orientation which is not perpendicular to the feed screw within the dispensing package as measured by a suitable angle measure or deflection gauge) so that the pressure on the product during extrusion is uniform. By intermittently retracting the elevator a suitable distance, discrete amounts of the product (doses) are dispensed for each cycle and the residual pressure on the product is relieved, preventing it from weeping onto the applicating surface of the dispensing package. Dispensing packages in accordance with this method are discussed in detail in U.S. Pat. No. 5,000,356 to Johnson et al., which is incorporated herein by reference.
One of the most common methods for filling cosmetic cream into a swivel-up dispensing package is to pour the cosmetic cream as liquid into the opened top end of the dispensing package. Unfortunately, the cosmetic cream in liquid form often undesirably leaks past the elevator. One method to fix this problem is to provide a seal bead completely surrounding the elevator. However, when this method is used the interference between the seal bead and the inner walls of the dispensing package is substantial and results in partial or no retraction of the elevator as discussed in U.S. Pat. No. 5,000,356 to Johnson et al. When a seal bead completely surrounding the elevator is not used, the elevator is now free-floating (experiencing minimal contact pressure with inner wall of the container body thus allowing the elevator to be retractable) but tends to lose its proper orientation of being perpendicular to the feed screw within the dispensing package during use. When the elevator is not properly oriented within the dispensing package, the product is dispensed non-uniformly and the pressure of the product against the perforated dome is not uniform thus resulting in non-uniform pressure relief by the elevator and weeping of the product.
It is, therefore, desirable to provide a dispensing package having a sealing system which effectively seals the dispensing package to prevent leakage during filling of the product from the top, while also providing a free-floating elevator which responds to the retracting action of the feed screw to prevent weeping of product onto the applicating surface while achieving proper orientation of being perpendicular to the feed screw within the dispensing package during use.